For loading of mass or bulk material loading machines long have been in use which are equipped with a loading bucket, mostly wheel-equipped machines or so-called wheel loaders. Such machines cooperate with transport vehicles in the form of trucks or the like for removal of the bulk material, at least for longer transport distances. On the other hand, the use of separate trucks for the transport of the bulk material for shorter transport distances is unnecessary since the loading machine can be used also for the transport. This last-mentioned method has particularly become applied in mines, tunnelling works and other places where the space is restricted and the transport distances relatively short, of the order of less than 500 m. For economical reasons the development of such machines has moved towards ever-increasing machines sizes. In practical use, as large a machine as altogether there is room for within a mine or tunnel gallery, now is applied. The bucket volumes of such machines now exceed 6 m.sup.3 and the load weights are of the magnitude of 15 metric tons.
It is obvious that such load weights require great wheels on the loading machine with subsequent increased wheel radius and hence increased distance of the centre of gravity of the load in the bucket from the adjacent wheel axle. In its turn, this requires a more and more rearwardly moved location of the heaviest parts of the machine such as the engine and the like for counter-balancing the load in the bucket.
These conditions imply, however, that the load variations, particularly concerning the wheel axle which is closest to the bucket, will be very great and the machine will have poor driving characteristics, particularly at full load. Such a load distribution at full load also results in a rapid wear of the tires, particularly on the wheels closest to the bucket, as well as rapid wear of the machine as a whole, dependent on how it is operated. During loading the machine is driven with full power into the heap of bulk material to be loaded. Then the operator of the machine, while progressively raising and rearwardly tilting the bucket in jerks, moves the machine into the heap in order to maximize the volume of material in the bucket as far as possible. In mines where the environment is extremely straining the wear of the machine of course will be still worse.
In order to achieve a better load distribution and hence a reduced wear of the machine or vehicle for the uses in question there have previously been made various suggestions and among those there can be referred to the Swedish Patent Specification No. 222,654. In this specification is disclosed a loading vehicle with a loading basket in which the basket-carrying portion of the vehicle is provided with a loading bucket attachment in order to allow self-loading of the vehicle. The loading bucket turned out to be too small in relation to the load basket volume, making it necessary progressively to move the vehicle into the heap of bulk material as the loading proceeded. Another suggestion of similar type is described in the Swedish Patent Specification No. 305,634. This specification disclosed a self-loading vehicle or a loading machine equipped with a tiltable load basket. Although such structure implied substantial improvements when compared with the structure according to said first-mentioned Swedish Patent Specification, the loading of the load basket by means of the bucket still required progressive movements of the vehicle, even if the loaded vehicle exhibits a more advantageous weight distribution in loaded condition.